fix(honcho): auto-enable when API key is present

Fixes #241

When users set HONCHO_API_KEY via `hermes config set` or environment
variable, they expect the integration to activate. Previously, the
`enabled` flag defaulted to `false` when reading from global config,
requiring users to also explicitly enable Honcho.

This change auto-enables Honcho when:
- An API key is present (from config file or env var)
- AND `enabled` is not explicitly set to `false` in the config

Users who want to disable Honcho while keeping the API key can still
set `enabled: false` in their config.

Also adds unit tests for the auto-enable behavior.

tests/test_honcho_client_config.py

@@ -0,0 +1,105 @@
+"""Tests for Honcho client configuration."""
+
+import json
+import os
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from honcho_integration.client import HonchoClientConfig
+
+
+class TestHonchoClientConfigAutoEnable:
+    """Test auto-enable behavior when API key is present."""
+
+    def test_auto_enables_when_api_key_present_no_explicit_enabled(self, tmp_path):
+        """When API key exists and enabled is not set, should auto-enable."""
+        config_path = tmp_path / "config.json"
+        config_path.write_text(json.dumps({
+            "apiKey": "test-api-key-12345",
+            # Note: no "enabled" field
+        }))
+
+        cfg = HonchoClientConfig.from_global_config(config_path=config_path)
+
+        assert cfg.api_key == "test-api-key-12345"
+        assert cfg.enabled is True  # Auto-enabled because API key exists
+
+    def test_respects_explicit_enabled_false(self, tmp_path):
+        """When enabled is explicitly False, should stay disabled even with API key."""
+        config_path = tmp_path / "config.json"
+        config_path.write_text(json.dumps({
+            "apiKey": "test-api-key-12345",
+            "enabled": False,  # Explicitly disabled
+        }))
+
+        cfg = HonchoClientConfig.from_global_config(config_path=config_path)
+
+        assert cfg.api_key == "test-api-key-12345"
+        assert cfg.enabled is False  # Respects explicit setting
+
+    def test_respects_explicit_enabled_true(self, tmp_path):
+        """When enabled is explicitly True, should be enabled."""
+        config_path = tmp_path / "config.json"
+        config_path.write_text(json.dumps({
+            "apiKey": "test-api-key-12345",
+            "enabled": True,
+        }))
+
+        cfg = HonchoClientConfig.from_global_config(config_path=config_path)
+
+        assert cfg.api_key == "test-api-key-12345"
+        assert cfg.enabled is True
+
+    def test_disabled_when_no_api_key_and_no_explicit_enabled(self, tmp_path):
+        """When no API key and enabled not set, should be disabled."""
+        config_path = tmp_path / "config.json"
+        config_path.write_text(json.dumps({
+            "workspace": "test",
+            # No apiKey, no enabled
+        }))
+
+        # Clear env var if set
+        env_key = os.environ.pop("HONCHO_API_KEY", None)
+        try:
+            cfg = HonchoClientConfig.from_global_config(config_path=config_path)
+            assert cfg.api_key is None
+            assert cfg.enabled is False  # No API key = not enabled
+        finally:
+            if env_key:
+                os.environ["HONCHO_API_KEY"] = env_key
+
+    def test_auto_enables_with_env_var_api_key(self, tmp_path, monkeypatch):
+        """When API key is in env var (not config), should auto-enable."""
+        config_path = tmp_path / "config.json"
+        config_path.write_text(json.dumps({
+            "workspace": "test",
+            # No apiKey in config
+        }))
+
+        monkeypatch.setenv("HONCHO_API_KEY", "env-api-key-67890")
+
+        cfg = HonchoClientConfig.from_global_config(config_path=config_path)
+
+        assert cfg.api_key == "env-api-key-67890"
+        assert cfg.enabled is True  # Auto-enabled from env var API key
+
+    def test_from_env_always_enabled(self, monkeypatch):
+        """from_env() should always set enabled=True."""
+        monkeypatch.setenv("HONCHO_API_KEY", "env-test-key")
+
+        cfg = HonchoClientConfig.from_env()
+
+        assert cfg.api_key == "env-test-key"
+        assert cfg.enabled is True
+
+    def test_falls_back_to_env_when_no_config_file(self, tmp_path, monkeypatch):
+        """When config file doesn't exist, should fall back to from_env()."""
+        nonexistent = tmp_path / "nonexistent.json"
+        monkeypatch.setenv("HONCHO_API_KEY", "fallback-key")
+
+        cfg = HonchoClientConfig.from_global_config(config_path=nonexistent)
+
+        assert cfg.api_key == "fallback-key"
+        assert cfg.enabled is True  # from_env() sets enabled=True